High-pressure fuel pump

A high-pressure fuel pump, for supplying a high-pressure fuel to an internal combustion engine, said pump comprising:

• a housing;
• a cylinder arranged in said housing;
• a piston received in said cylinder for reciprocating sliding movement for drawing fuel into said cylinder and pressurizing it;
• a tappet arranged at one end portion of said housing for reciprocating motion therein and adapted to contact a cam, which rotates together with a camshaft of said internal combustion engine, so as to transmit a driving force of said internal combustion engine to said piston;
• and
• a sleeve arranged between said tappet and said housing and clearance fitted relative to at least one of an outer peripheral surface of said tappet and an inner peripheral surface of said housing;
• wherein said tappet is caused to rotate on its own axis under the action of a frictional force generated between said cam and said tappet, and wherein said axis around which said tappet rotates extends in the same direction as that of the reciprocating sliding movement of said piston,
• wherein a wide groove extending in a circumferential direction of said tappet is formed on the outer peripheral surface of said tappet, and said sleeve of a C-shaped configuration is fitted into said groove.